Cathode, all-solid-state battery and methods for producing them

Patent metadata

Field	Value
Publication number	US-2019372103-A1
Application number	US-201916407352-A
Country	US
Kind code	A1
Filing date	May 9, 2019
Priority date	May 29, 2018
Publication date	Dec 5, 2019
Grant date	—

Abstract

Provided is a cathode that is configured to decrease battery resistance when it is used in an all-solid-state battery, and a method for producing the cathode. Disclosed is a cathode comprising a cathode layer for all-solid-state batteries, wherein the cathode layer contains cathode active material particles and solid electrolyte particles; wherein at least one of the cathode active material particles and the solid electrolyte particles contain a phosphorus element; and wherein, in a photoelectron spectrum by X-ray photoelectron spectroscopy measurement of the cathode layer, a P peak intensity ratio (A/B), which is derived from the phosphorus element, of a signal intensity A at a binding energy of 131.6 eV to a signal intensity B at a binding energy of 133.1 eV, is larger than 0.58.

First claim

1 . A cathode comprising a cathode layer for all-solid-state batteries,
wherein the cathode layer contains cathode active material particles and solid electrolyte particles; wherein at least one of the cathode active material particles and the solid electrolyte particles contain a phosphorus element; and wherein, in a photoelectron spectrum by X-ray photoelectron spectroscopy measurement of the cathode layer, a P peak intensity ratio (A/B), which is derived from the phosphorus element, of a signal intensity A at a binding energy of 131.6 eV to a signal intensity B at a binding energy of 133.1 eV, is larger than 0.58.

2 . The cathode according to claim 1 , wherein the cathode layer contains composite active material particles comprising the cathode active material particles and a lithium ion conducting oxide, the lithium ion conducting oxide coating at least part of the surface of the cathode active material particles.

3 . The cathode according to claim 2 , wherein the lithium ion conducting oxide is at least one selected from the group consisting of lithium niobate, lithium titanate, lithium lanthanum zirconate, lithium tantalate and lithium tungstate.

4 . The cathode according to claim 1 , wherein the solid electrolyte particles are sulfide-based solid electrolyte particles.

5 . The cathode according to claim 1 , wherein a moisture content of the cathode active material particles is 70 ppm or less.

6 . An all-solid-state battery comprising:
a cathode comprising a cathode layer, an anode comprising an anode layer, and a solid electrolyte layer disposed between the cathode layer and the anode layer, wherein the cathode is the cathode defined by claim 1 .

7 . A method for producing a cathode comprising a cathode layer for all-solid-state batteries, the method comprising:
preparing cathode active material particles; vacuum-drying the cathode active material particles at a temperature of 120° C. or more and 300° C. or less for one hour or more; mixing the cathode active material particles with solid electrolyte particles to obtain a cathode mix; and forming the cathode mix to obtain the cathode layer, wherein at least one of the cathode active material particles and the solid electrolyte particles contain a phosphorus element, and wherein, in a photoelectron spectrum by a X-ray photoelectron spectroscopy measurement of the cathode layer, a P peak intensity ratio (A/B), which is derived from the phosphorus element, of a signal intensity A at a binding energy of 131.6 eV to a signal intensity B at a binding energy of 133.1 eV, is larger than 0.58.

8 . The method for producing the cathode according to claim 7 , wherein, in the preparing, composite active material particles comprising the cathode active material particles and a lithium ion conducting oxide, the lithium ion conducting oxide coating at least part of the surface of the cathode active material particles, are prepared.

9 . The method for producing the cathode according to claim 8 , wherein, in the preparing, a precursor of the composite active material particles is obtained by drying, on the surface of the cathode active material particles, a peroxo complex aqueous solution containing an element that will compose the lithium ion conducting oxide, and the composite active material particles are obtained by sintering the precursor.

10 . The method for producing the cathode according to claim 7 , wherein the solid electrolyte particles are sulfide-based solid electrolyte particles.

11 . A method for producing an all-solid-state battery comprising:
a cathode comprising a cathode layer, an anode comprising an anode layer, and a solid electrolyte layer disposed between the cathode layer and the anode layer, wherein the cathode is a cathode produced by the production method defined by claim 7 .

Assignees

• Toyota Motor Co Ltd

Inventors

• Miki Nariaki

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M4/362 Primary

  Composites · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M2300/0068

  inorganic · CPC title